erm - this was awhile ago, but if you have 3 standard 3phase leads then
taking any two of them will give you 220v. I i seem to remeber something
about star and delta wiring. cant remeber where it comes in. the drop from
380 to 220 is because of the 120 deg phase diff between the 3 phases.

john

> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Harrison Cooper
> Sent: 15 October 1999 02:18
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [OT] got a problem powering my PIC based device now (380-220
> xfrm er needed)
>
>
> Just when I thought I had everything covered, something new comes up.
>
> I've got some PIC based devices, with a built in small linear
> supply.  I use
> a 220/110 input transformer, and up to now have always had either voltage
> available.  Or could figure out a way to get it.
>
> But now a client has 380VAC 3 phase, and demands (I hate that!)
> to use only
> 220VAC single phase for all control voltages.
>
> I can find sources on 380 to 110 transformers, but can't seem to locate
> anything that will take 380 to 220, in either a control or
> buck-boost.  All
> I need is about 250VA.
>
> And I cannot do this in a custom, the quantities don't warrant the expense
> on that.
>
> Anyone know of a vendor that has this in the standard line-up?
>